CVE-2008-1375 in Linux
Summary
by MITRE
Race condition in the directory notification subsystem (dnotify) in Linux kernel 2.6.x before 2.6.24.6, and 2.6.25 before 2.6.25.1, allows local users to cause a denial of service (OOPS) and possibly gain privileges via unspecified vectors.
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Analysis
by VulDB Data Team • 08/10/2019
The vulnerability described in CVE-2008-1375 represents a critical race condition within the Linux kernel's directory notification subsystem known as dnotify. This flaw exists in kernel versions prior to 2.6.24.6 and 2.6.25.1, creating a window of opportunity for malicious actors to exploit the system's handling of directory change notifications. The dnotify mechanism is designed to inform processes when files or directories within a monitored path are modified, creating a fundamental security and stability concern when this subsystem fails to properly manage concurrent access patterns.
The technical implementation of this race condition occurs within the kernel's directory notification handling code where multiple threads or processes can simultaneously access and modify directory notification structures without proper synchronization mechanisms. This lack of proper locking or atomic operations allows for unpredictable behavior when directory change events are processed concurrently, leading to potential memory corruption scenarios. The vulnerability manifests as an OOPS (Oops! kernel panic) condition which results in system instability and denial of service, as the kernel cannot properly handle the corrupted state information.
From an operational impact perspective, this vulnerability provides local attackers with the capability to either disrupt system services through denial of service or potentially escalate privileges within the system. The race condition allows for memory corruption that can be leveraged to execute arbitrary code with kernel-level privileges, making this a particularly dangerous flaw for any system running vulnerable kernel versions. The attack vector is limited to local users since exploitation requires access to the system and the ability to manipulate directory notification mechanisms, but the potential for privilege escalation makes this a significant concern for system administrators.
The vulnerability aligns with CWE-362, which describes a race condition in concurrent execution environments, specifically focusing on the improper handling of concurrent access to shared resources. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques through kernel exploits and system resource manipulation. The exploitation process typically involves creating multiple concurrent processes that manipulate directory notification structures to trigger the race condition, potentially leading to kernel memory corruption that can be leveraged for privilege escalation.
Mitigation strategies for CVE-2008-1375 require immediate kernel updates to versions 2.6.24.6 or 2.6.25.1, which contain the necessary patches to address the race condition in the dnotify subsystem. System administrators should also implement monitoring solutions to detect unusual patterns in directory notification behavior that might indicate exploitation attempts. Additional defensive measures include restricting local user access where possible, implementing proper kernel hardening techniques, and maintaining comprehensive system logging to track potential exploitation attempts. The patch addresses the underlying synchronization issues in the kernel's directory notification handling code, ensuring that concurrent access to notification structures properly utilizes locking mechanisms to prevent the race condition from occurring.